Oscillating diaphragm pump



Sept. 14, 1965 G. R. ANDERsEN ETAL 3,205,829

OSCILLATING DIAPHRAGM PUMP Filed Oct. 4, 1962 ufgig.

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United States Patent O 3,205,829 OSCILLATING DIAPHRAGM PUMP Gerald R. Andersen and William W. Harris, Flint, and

Kenneth C. Kernen, Holly, Mich., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Oct. 4, 1962, Ser. No. 228,413 5 Claims. (Cl. 10S- 150) This invention relates to pumps and more particularly to diaphragm pumps specifically suited for feeding liquid fuel to an internal combustion engine.

An object of the present invention is to provide an improved pump of the diaphragm type which is of simple construction and which is characterized by a minimum of parts. To this end, an important feature of the invention is a diaphragm retained by protector plate means and which is oscillatable to effect a pumping action.

The above and other important features of the invention will now be described in detail in the specification and then pointed out more particularly in the appendedl claims.

In the drawings:

FIGURE 1 shows a sectional view through a pump constituting one embodiment of the invention; and

FIGURE 2 shows a sectional View taken along the line 2-2 of FIGURE 1 and disclosing the casting only.

FIGURE l shows a liquid fuel pump comprising a casing from which a rocker arm protrudes for actuation by a camshaft 12 of an internal combustion engine which the pump is adapted to serve. The casing comprises a a single casting or main body 14 which defines a pumping chamber 16, a fuel inlet chamber 18 and a fuel outlet chamber 20. The casting 14 is fitted with conventional inlet and outlet one-way valves 22 and 24 respectively for promoting ow through the pumping chamber.

A bottom cover 26 is fastened to the casting 14 by means of two screws such as the screw 28 with a diaphragm 30 interposed so that pulsator chambers 32 and 34 are provided in registry with the chambers 18 and 20 respectively. The chamber 18 is provided with an inlet for fuel as at 36 and the chamber 20 is provided with an outlet as at 38.

The casting 14 has an integral ange 40 adapted to be attached to the side of an engine so that the rocker arm 10 may properly engage a cam 42 of the camshaft 12. A chamber 44 of the casting 14 is so made as to communicate with the crankcase of the engine and this chamber has an opening 46 which is sealed by a portion of a diaphragm 48. The periphery of the diaphragm 48 is held to the casing by means of a heavy metallic pressure ring 50 and the latter is provided with a large orifice 52 and a small orifice 54. The small orifice 54 is in registry with the opening 46 leaving a portion 56 of the pumping diaphragm 48 free for flexure. The pressure ring 50 and the diaphragm 48 are held tightly to the casting 14 by means of a sheet metal cover 58 which is crimped as at 60 around a thickened rim 61 extending around a major portion of the periphery of the casting 14. One end of the cover 58, however, rests'on a shoulder 65 of the casting.

Special diaphragm protector plate means 62 is provided on a shaft 66 for oscillatable movement about the latter. The shaft lies in a plane adjacent to that of the general plane of the plate means 62 and traverses the chamber 44 of the casting 14 and is retained in a bore 67. The inside of the protector means 62 is fitted with a downwardly extended pin 68 which is welded to the protector means. This pin 68 extends down through the openings 54 and 46 and is tightly embraced by the portion 56 of the diaphragm 48. The lower end of the pin 68 is adapted to contact a face 70 of a plate 72 which is welded to the 3,205,829 vPatented Sept. 14, 1965 ICC rocker arm 10. The plate 72 has a shoulder or surface which, under the urging of a coil spring 76 acting between a protuberance 78 on the casting 14 and a protuberance 80 on the plate 72, acts as a stop 74 prior to installation of the pump on an engine.

The cover 58 is of such size as to enclose not only the diaphragm protector means 62 but also a main pumping spring 82. One end of the spring 82 is firmly located by a depressed portion 84 of the cover and the lower end of the spring is firmly seated in an annular recess formed on the protector means 62. To the inside of the protector means 62 is welded a circular plate 88 which has a central portion passing through an opening in the diaphragm 48 for close attachment to the upper plate portion of the protector means 62. The configuration of the circular plate 88 and the main plate of the protector means 62 are such as to create a substantial and annular bight in the diaphragm 48 extending into the pumping chamber 16.

The protector means 62 has two depending and integral arms such as the arm 92. These arms extend downwardly into pockets 94 and 96 of the casting 14 and are journaled on the shaft 66. These pockets are not in communication with the chamber 44.

In the operation of the pump, the engine camshaft 12 rotates with the result that the rocker arm 10 and its associated plate 72 oscillate about the shaft 66. The spring 76 insures continual contact of the rocker arm 10 with the cam 42. With this oscillation of the rocker arm 10, the protector plate means 62 is also oscillated about the shaft 66 to an extent dependent upon fuel demand and as the diaphragm 48 moves upwardly in a given cycle, it forms a suction stroke drawing fuel in from the line 36 and through the inlet chamber 18 and the valve 22 to the pumping chamber 16. This compresses the spring 82. As the diaphragm is subsequently lowered because of the action of the spring 82, fuel in the pumping chamber 16 is forced through the valve 24 into the chamber 20 and to the engine by way of the outlet 38. In the event that the outlet fuel pressure is equal to the fuel pressure required by the engine, the pin 68 will lose contact with the surface 70 and will not again establish contact until the outlet fuel pressure drops.

It will be noted that only one casting is needed in the construction illustrated. It should also be noted that the pumping diaphragm 48 serves as an oil seal between the engine crankcase or the oil chamber and the fuel chambers. It should also be noted that the pumping diaphragm 48 is sealed into firm position by the peculiar pressure ring and crimped cover construction.

We claim:

1. A pump comprising a casing, a diaphragm cooperating with said casing to form a pumping chamber, protector plate means in the form of a rigid lever retaining a movable portion of said diaphragm and having a pivotal mounting on said casing, spring means urging said protector plate means to move in one direction in an arcuate path about said pivotal mounting thereby effecting a pumping stroke, power means for driving said protector plate means in the other direction in said path and against said spring means thereby effecting a suction stroke, and said pivotal mounting being at one side of said arcuate path.

2. A pump comprising a casing, a diaphragm cooperating with said casing to form a pumping chamber, protector plate means retaining a movable portion of said diaphragm and having a pivotal mounting =on said cas-ing at one side of said pumping chamber and adjacent to the plane of said protector plate means, a cover for said diaphragm, a pressure ring confined between said diaphragm and said cover, spring means in said cover urging said protector plate means and movable portion of said diaphragm to move in the direction of the pumping chamber and about said pivotal mounting, and means including a rocker arm extending to the exterior of said casing for driving said protector plate means and movable portion of said diaphragm in the other direction and against said spring means.

3. A liquid fuel pump comprising a casing, said casing including a main casting retaining inlet and outlet ports and valves .and a sheet metal cover, a pumping diaphragm and a diaphragm pressure ring of metal interposed between said casting and cover, said diaphragm cooperating with said casting in dening a pumping chamber, protector plate means retaining a movable portion of said diaphragm and having a pivotal mounting within said cast ing at one side of said chamber and adjacent to the plane of the protector plate means, and means for oscillating said pumping diaphragm and protector plate means about the axis of said pivotal mounting.

4. A pump comprising a casing having a main body and a cover, a diaphragm interposed between said main body and cover and cooperating with said main body in dening a pumping chamber, said main body determining a xed cross sectional area of said pumping chamber, protector plate means retaining a movable portion of said diaphragm andhaving a pivotal mounting within said casing, said pivotal mounting being in the plane of said fixed cross sectional area, spring means urging said protector plate means and movable portion of said diaphragm in one arcuate direction about said pivotal mounting to effect a pumping stroke, and means extending through the said main body for urging said protector plate means and movable portion of said diaphragm in the opposite arcuate direction about said pivotal mounting to eiect a suction stroke.

5. A pump comprising a casing, said casing including a casting having a rim and a sheet metal cover crimped to said rim of said casting, a diaphragm interposed between said cover and said casting to form a pumping chamber in said casting, protector plate means retaining a movable portion of said diaphragm in registry with said pumping chamber and being in the form of a unitary lever having a pivotal mounting on said casing to one side of said pumping chamber, spring means in said cover and acting on said diaphragm, said protector plate means and movable diaphragm portion being adapted to move in one arcuate direction about the said pivotal mounting, and means for driving said-protector plate means and diaphragm in the opposite arcuate direction and against said spring means.

References Cited by the Examiner UNITED STATES PATENTS 2,169,827 8/39 Whitted 103-150 2,429,441 10/ 47 Williams 230-55 2,518,298 8/50 Erickson 103-150 2,873,686 2/59 Harry 103-150 2,969,746 1/61 Smith 103-150 LAURENCE V. EFNER, Primary Examiner.

WARREN E. COLEMAN, Examiner. 

1. A PUMP COMPRISING A CASING, A DIAPHRAGM COOPERATING WITH SAID CASING TO FORM A PUMPING CHAMBER, PROTECTOR PLATE MEANS IN THE FORM OF A RIGID LEVER RETAINING A MOVABLE PORTION OF SAID DIAPHRAGM AND HAVING A PIVOTAL MOUNTING ON SAID CASING, SPRING MEANS URGING SAID PROTECTOR PLATE MEANS TO MOVE IN ONE DIRECTION IN AN ARCUATE PATH ABOUT SAID PIVOTAL MOUNTING THEREBY EFFECTING A PUMPING STROKE, POWER MEANS FOR DRIVING SAID PROTECTOR PLATE MEANS IN THE OTHER DIRECTION IN SAID PATH AND AGAINST SAID SPRING MEANS THEREBY EFFECTING A SUCTION STROKE, AND SAID PIVOTAL MOUNTING BEING AT ONE SIDE OF SAID ARCUATE PATH. 